The doughnut and coffee chain said Wednesday delivery will be offered in Dallas this week and spread to Atlanta, Chicago, Los Angeles and Washington in coming weeks. Delivery orders need to be made on the app or website of DoorDash, the delivery company that Dunkin' Donuts is partnering with.

Tests of on-the-go ordering are taking place at stores in Portland, Maine. Customers place orders on the Dunkin' Donuts app in advance and pick them up at a store.

With the tests, Dunkin' Donuts is catching up with rivals. Seattle-based coffee chain Starbucks Corp. already offers on-the-go ordering at 7,400 company-owned U.S. stores and is testing deliveries in certain cities.